There have been proposed several kinds of solid golf balls which are specified by the weight and density of the ball and the density and hardness of the core and cover. They are disclosed in Japanese Patent Nos. 3005066, 2924698, 2820060, 3067611, 3120717, and 2888168, and Japanese Patent Laid-open Nos. Hei 10-230023 and Hei 9-168610.
Unfortunately, these conventional solid golf balls are improved in flying distance but are poor in crack resistance. Moreover, some of them are good in crack resistance but poor in flying performance due to excessive spin.
In other words, none of them are satisfactory in both flying performance and crack resistance. Especially, they do not make the novice golfers satisfy with flying distance who merely achieve the head speed in the order of 30 m/s.